Plastic-lead mushrooming bullet



Oct. 24, 1967 RAPP PLASTIC-LEAD MUSHROOMING BULLET Filed Dec. 10, 1965 AIl w w B Li lll INVENTOR REINHOLD RAPP BY ZQNIQ Q/ ATTORN B UnitedStates Patent 3,348,486 PLASTIC-LEAD MUSHROOMING BULLET Reinhold Rapp,Stadeln, Bavaria, Germany, assignor to Dynamit Nobel A.G., Troisdorf,Germany Filed Dec. 10, 1965, Ser. No. 512,985 Claims priority,application Germany, Dec. 12, 1964, D 46,045 22 Claims. (Cl. 102-92.3)

ABSTRACT OF "nan DISCLOSURE several axially aligned supporting shouldersspaced radially outwardly from the wedge for supporting the exterior ofthe core against relative movement and defining with the wedge anannular space therebetween to allow the above-mentioned mushroomingeffect. The core may be provided with a plurality of annular rings onits outer surface and a central rearwardly opening aperture for weightreduction and to provide desired flight characteristics.

Background of the invention It has been an aim for quite some time withcartridges to increase the bullet velocity and at the same time toreduce the bullet weight. By reason of the difficulties to so matchthese two factors to one another that the desired effect is achievedthereby, especially a corresponding behavior of the bullet in the animalbody, these efforts heretofore did not always bring about the desiredsuccess.

Summary of the invention Consequently, a new approach is followedaccording to the present invention for the solution of theaforementioned problem with cased or covered bullets for cartridgeswhereby one starts with the premise that increased bullet velocitieswith simultaneously reduced bullet weight only makes sense and isappropriate only if at the same time the disintegration of the bullet orthe desired mushrooming of the core can take place rapidly. Accordingly,the present invention proposes to make the bullet case or jacket ofthermoplastic material, preferably of polyethylene, polystyrene, or hardpolyvinyl chloride, and the bullet core in a known manner of lead, andto so construct the two parts that the core is retained between thesolidly constructed bullet jacket tip and the inwardly flanged bulletjacket end. The use of these materials having a very different specificweight makes it possible by a corresponding selection of the dimensionand volumes of plastic bullet jackets and lead core, i.e., bycorresponding matching of the proportions thereof to the over-alldimensions and over-all volume, to influence the weight and center ofgravity of the bullet over a very wide range and therewith to match thesame to very different ballistic requirements as regards shell velocity,penetrating force and flight or ballistic properties. Furthermore, theconstruction of the bullet jacket of plastic material offers theadvantage that the latter opposes a hardly significant resistance duringthe mushrooming of the core upon impact on the animal body, at least,however, a considerably smaller resistance than the customary bulletjackets of steel or metal in use heretofore.

This ready and advantageous mushrooming of the core can be furtherconsiderably improved if, according to a further proposal of the presentinvention, the core is axially supported in the jacket or casing in thedirection toward the bullet tip along a ring-shaped rim strip of itsforward end face, i.e., in such a manner that between the central areaof the forward end face of the core and the oppositely disposed centralarea of the case or jacket tip, a hollow space is created. Upon impactof the bullet on the target, this has as a consequence that the corematerial is held back in the abutting or supported rim area whereas thecore material disposed in the central unsupported area moves forwardlyunder the influence of the inertia until it finally impinges against orhits upon the bullet jacket tip and then seeks to deflect laterallywhereby it forces away outwardly the material disposed in the rim area,thus bursting open the bullet jacket or case or shears olf the samedirectly behind the solid case or jacket tip.

A further advantageous measure according to-the present invention forimproving the mushrooming of the bullet core resides in that the latteris provided at the forward end face thereof with a central conicalaperture or recess, by means of which the bullet core is supported onacor-v respondingly constructed conical extension of the bullet jacket orcasing or also on a separate damming body insorted in the axialdirection between the bullet jacket tip and the core. This measureeffects immediately upon impact of the bullet at the target, adeflection of the material forming the center of the core both-forwardlyand outwardly at an inclination corresponding to the conical inclinationof recess and extension so that the mushroom? ing operation is initiateddirectly upon impact of the bullet and especially also the shearingeffect on the'bullet jacket is considerably reinforcedor'enhancedthereby;

The arrangement of a separate damming body offers thereby not only thepossibility to influence the mushrooming by means of the damming body bya selection of a correspondingly hard material and totinfiuence thebullet velocity by selection of a more or less heavy material, butespecially also the possibility to construct the bullet jacket tip,shearing off upon mushrooming of the core, of such heavy weight and withsuch penetrating force that a slug channel is achieved with certainty inthe animal body. 7

According to a further proposal of the present invention, provision ismade to construct the core at the for-- ward end by means of aconstriction in such a manner as to taper conicallytoward therear and toanchor the core the-reat by means of an internal annularly shapedreinforcement of the bullet jacket of corresponding'shape and engaginginto this constriction of the core. Not only the requisite good securingof the core in the'jacket is achieved by this measure but also at thesame time the desired easy and good mushrooming ofthe core upon impactof the bullet at the target is favored as'the outer forward end of thecore 1s effective along its entire circumference as a pointed wedgedirected obliquely forwardly and outwardly. i

The possibilities to influence the velocity, the weight, and the centerof gravity location of the bullet according to the present invention inthe desired manner are not limited to varying the wall thickness of thebullet jacket and the length of its solid tip and to then constructcorre spondingly the core with :a more or less large radial and axialdimension, rather an influencing in the desired sense also exists by thefact that the core is provided along the circumference with a more orless large number of annular grooves of corresponding width and depthand/or is provided with a more or less deep recess of correspond- 7Patented Oct. 24,1967,

to a good adaptability of the bullet to the given constructions anddimensions of the barrel of the gun as the possibility exists therebyfor the core material to deflect and yield correspondingly in the axialdirection with strong radial pressures.

Accordingly, it is an object of the present invention to provide acartridge which is simple in construction, yet avoids the shortcomingsencountered heretofore with the prior art constructions -in an effectivemanner.

Anotherobject of the present invention resides in the provision of abullet jacket for cartridges in which the bullet velocity can beincreased while at the same time the bullet weight can be decreasedwithout affecting deleteriouslythe efficacy upon impact on the animal.

A further object of the present invention resides in a bullet jacket ofthe type described above which utilizes readily available materials thatenhance the mushrooming explosion of the core in a rapid manner.

Still another object of the present invention resides in a bullet jacketor envelope of plastic material which permits variation over anextraordinarily wide range of the volume, weight, and location of thecenter of gravity of the 'bulletand'therewith enables an adaptation ofthe particular bullet to the prerequisite ballistic conditions undergiven circumstances.

Still a further object of the present invention resides in a bulletjacket for cartridges which at least greatly reduces the resistanceencountered by the core during the mushrooming release of the core uponimpact on the animal body.

Another 'object of the present invention resides in the construction andarrangement ofa bullet jacket and core therefor, which not onlyfacilitates the mushrooming release of the core upon impact but alsoassures an initiation of 'such mushrooming directly upon impact of thebullet "on the animal.

These and further objects, features and advantages of the presentinvention will become more obvious from the following description whentaken in connection with the accompanying drawing, which shows, forpurposes of illustration only, two embodiments in accordance with thepresent invention, and wherein:

Brief description of the drawing FIGURE 1 is an axial cross-sectionalview through a first embodiment of a bullet in accordance with thepresent invention :provided with'an internal conical damming body formedon the bullet jacket tip; and

FIGURE 2 is a partial 'axial cross-sectional view through amodifiedembodiment of'a bullet in accordance with the present invention providedwith a separate damming body.

Detailed description Referring now to the drawing wherein like referencenumerals are used throughout the two views to designate like parts, andmore particularly to FIGURE 1, approximately the forward third of thebullet jacket 1 made of synthetic plastic material and surrounding thelead core 3 is constructed as solid bullet tip 2. On the inside of thebullet jacket 1, the bullet tip 2 extends into the projection 4 ofconically truncated shape and engages with this projection 4 into theconically truncated recess 6 formed into the forward end face 5 of thecore 3. The forward end 7 of the core 3 as well as the adjoining area 8of the jacket 1 are provided, as viewed in axial cross section, withidentical complementary Z-shaped configurations so that the jacket 1 andthe core 3 mutually face one another by means of the plane annularsurfaces 9 disposed one behind the other as well as the conical surface10 and are thus mutually fixed in the axial direction. In its centralpart, the core 3 is provided with the two shallow wide annular grooves11. The inwardly flanged rear end of the jacket 1 is provided with anaperture 12 closed by the disk 13. Reference numeral 14 designates acentral aperture provided in the rear part of the core 3.

The shell tip 2, the bullet tip 2-and analogously, of course, also thecore 3-may be of solid construction over a more or less large axialextent whence both an influencing of the bullet weight and therewith ofthe bullet velocity as also of the location of the center of gravity ofthe bullet can be achieved. The same, however, can also be achieved to acertain extent in that the cross-sectional dimensions of the core 3 aswell as the wall conditions of the jacket 1 are varied in an analogousmanner. Further possibilities for that purpose exist by the constructionof a more or less large number of annular grooves of corresponding widthand depth and also by a corresponding dimension of the recess oraperture 14 both as regards it depth as well as its cross-sectionaldimensions.

The recess 6 and extension 4 may'also be constructed conically with apoint or apex. Possibly, however, the aperture 6 by itself could beconstructed conically with a point or apex and the extension 4 could beretained in the illustrated truncated conical shape. It is furthermoreclear that the possibilities of construction of the recess 6 and of theextension 4 is not limited to the shape of a cone but instead othershapes may be realized, by means of which the intended rapid and easymushrooming of the core is achieved.

The forward end of the bullet tip 2 may be provided also with aconventional disintegration aperture and still considered to besubstantially rigid.

According to FIGURE 2, in which the parts corresponding to those ofFIGURE 1 are designated by the same reference numerals, the separatedamming body 15 is arranged in the axial direction between the solidbullet tip 2 constructed of much smaller dimension that in FIGURE 1 andthe core 3. One is able by appropriate selection of the material of thedamming body 15, such as a relatively unyielding thermoplastic materialor thermosetting plastic material, to influence in the desired mannerthe mushrooming operation as also the bullet weight and in dependence ofthe latter correspondingly also the velocity and location of the centerof gravity of the bullet. The core 3 is constructed in that case with alarger number of trapezoidally shaped annular grooves 11 andtransitional sections disposed thcrebctween whereby the adaptability ofthe shell to the barrel of the gun is still further improved.

With both embodiments, upon impact of the bullet on the target, the core3 is held back in its rim area by the annular surface '9 of the bulletjacket 1, whereas, in contrast thereto, the inwardly adjoining annularlyshaped area of the core 3 is displaced forwardly by reason of lack of anabutment under the effect of the inertia. The inwardly adjoiningrim-shaped area of the core 3 is thereby deflected obliquely forward andoutwardly by the extension 4 also holding back the material of the corecenter and effecting a damming action and is thereby scattered anddriven apart so that the jacket 1 bursts open about the entirecircumference within the area of the edge 16 by the wedging effect andthus the desired mushrooming of the core can now take place without anyconsiderable resistance.

While I have shown and described two embodiments in accordance with thepresent invention, it is understood that the same is not limited theretobut is susceptible of numerous changes and modifications as known to aperson skilled in the art, and I therefore do not wish to be limited tothe details shown and described herein but intend to cover all suchchanges and modifications as are encompassed by the scope of theappended claims.

I claim:

1. A bullet for cartridges, having an axis, an axial forward end and anaxial rear end; a bullet jacket of synthetic plastic material; a core oflead material within said jacket; said jacket having a forward endsubstantially rigid jacket tip and an axially extending generallytubular portion, substantially enclosing said core at the forward endand the sides, respectively; said jacket tip having a rearwardlyextending and inwardly tapered wedge means for engaging the centralportion of said core to mushroom the forward end of said core outwardlyand forwardly upon relative axial movement toward each other.

2. The bullet according to claim 1, wherein said synthetic plasticmaterial is selected from the group consisting of polypropylene,polyethylene and hard polyvinyl chloride.

3. The bullet according to claim '1, wherein said core has an outerforwardly facing annular shoulder and said jacket has a rearwardlyfacing annular shoulder engaging said core shoulder.

4. The bullet according to claim 3, wherein said shoulders aresubstantially perpendicular to the bullet axis.

5. The bullet according to claim 1, wherein said core has a forwardlyopening and widening cam aperture in its central portion generally ofthe same shape as and engaging said jacket wedge means.

6. The bullet according to claim 5, wherein said wedge means is separatefrom the remainder of said jacket.

7. The bullet according to claim 3, wherein each of said jacket and saidcore has second shoulders substantially identical to, axial-1y alignedwith and axially spaced from said first mentioned shoulders connectedtogether by a diagonally extending, as viewed in axial cross section,annular portion.

8. The bullet according to claim 1, wherein said core has at least oneannular groove on its exterior substantially symmetrical with the axisand forming an annular empty space between said core and said jacket.

9. The bullet according to claim 1, wherein said core has a plurality ofannular grooves on its exterior substantially symmetrical with the axisand forming annular empty spaces between said core and jacket.

10. The bullet according to claim 1, wherein said core is provided witha substantially central aperture opening rearwardly.

11. The bullet according to claim 10, further comprising closure meansfor closing said central aperture 12. The bullet according to claim 3,wherein said core has a forwardly opening and widening cam aperture inits central portion generally of the same shape as and engaging saidjacket wedge means.

'13. The bullet according to claim 12, wherein each of said jacket andsaid core has second shoulders substantially identical to, axiallyaligned with and axially spaced from said first mentioned shouldersconnected together by a diagonally extending, as viewed in axial crosssection, annular portion,

14. The bullet according to claim 13, wherein said core has at least oneannular groove on its exterior s'ubstantially symmetrical with the axisand forming an annular empty space between said core and said jacket.

15. The bullet according to claim 14, wherein said core is provided witha substantially central aperture opening rearwardly.

16. The bullet according to claim 7, wherein said core has at least oneannular groove on its exterior substantially symmetrical with the axisand forming an annular 7 empty space between said core and said jacket.

17. The bullet according to claim 1, wherein the rear- 7 21. The bulletaccording to claim '20, wherein said diagonally extending annularportion is substantially radially aligned and spaced outwardlyconcentric with said wedge means.

22. The bullet according to claim 21, wherein the rearward end of saidjacket includes an inwardly extending annular flange axially abutingagainst the rearward end of said core and wherein said tubular portionof said jacket is substantially cylindrical and said wedge means issubstantially conical.

References Cited UNITED STATES PATENTS 2,820,412 l/1958 Beeuwkes et a110291 X 3,110,262 11/1963 West 102-925 X 3,200,751 8/1965 Vitt 10292.53,247,795 4/1966 Abela 10291 X FOREIGN PATENTS 7,571 1906 Great Britain.

BENJAMIN A. BORCHELT, Primary Examiner. ROBERT F. STAHL, Examiner

1. A BULLET FOR CARTRIDGES, HAVING AN AXIS, AN AXIAL FORWARD END AND ANAXIAL REAR END; A BULLET JACKET OF SYNTHETIC PLASTIC MATERIAL; A CORE OFLEAD MATERIAL WITHIN SAID JACKET; SAID JACKET HAVING A FORWARD ENDSUBSTANTIALLY RIGID JACKET TIP AND AN AXIALLY EXTENDING GENERALLYTUBULAR PORTION, SUBSTANTIALLY ENCLOSING SAID CORE AT THE FORWARD ENDAND THE SIDE, RESPECTIVELY; SAID JACKET TIP HAVING A REARWARDLYEXTENDING AND INWARDLY TAPERED WEDGE MEANS FOR ENGAGING THE CENTRALPORTION OF SAID CORE TO MUSHROOM THE FORWARD END OF SAID CORE OUTWARDLYAND FORWARDLY UPON RELATIVE AXIAL MOVEMENT TOWARD EACH OTHER.